Iron Regulatory Protein 1
Iron Regulatory Protein 2
Iron-Regulatory Proteins
Iron
Aconitate Hydratase
Iron-Sulfur Proteins
Ferritins
Receptors, Transferrin
Apoferritins
Iron Chelating Agents
RNA-Binding Proteins
Iron Metabolism Disorders
Iron, Dietary
Deferoxamine
Homeostasis
RNA, Messenger
Cation Transport Proteins
Transferrin
Untranslated Regions
Response Elements
Iron Overload
Hemochromatosis
Molecular Sequence Data
Duodenum
Heme
Hepcidins
Gene Expression Regulation
Cytosol
Base Sequence
Protein Biosynthesis
Protein Binding
Nucleic Acid Conformation
RNA
Iron Isotopes
Binding Sites
Liver
Amino Acid Sequence
Iron Radioisotopes
Hydrogen Peroxide
Leucine-Responsive Regulatory Protein
Mutation
Oxidation-Reduction
Iron Compounds
Oxidative Stress
Oxygen
Blotting, Western
HeLa Cells
Inactivation of both RNA binding and aconitase activities of iron regulatory protein-1 by quinone-induced oxidative stress. (1/200)
Iron regulatory protein-1 (IRP-1) controls the expression of several mRNAs by binding to iron-responsive elements (IREs) in their untranslated regions. In iron-replete cells, a 4Fe-4S cluster converts IRP-1 to cytoplasmic aconitase. IRE binding activity is restored by cluster loss in response to iron starvation, NO, or extracellular H2O2. Here, we study the effects of intracellular quinone-induced oxidative stress on IRP-1. Treatment of murine B6 fibroblasts with menadione sodium bisulfite (MSB), a redox cycling drug, causes a modest activation of IRP-1 to bind to IREs within 15-30 min. However, IRE binding drops to basal levels within 60 min. Surprisingly, a remarkable loss of both IRE binding and aconitase activities of IRP-1 follows treatment with MSB for 1-2 h. These effects do not result from alterations in IRP-1 half-life, can be antagonized by the antioxidant N-acetylcysteine, and regulate IRE-containing mRNAs; the capacity of iron-starved MSB-treated cells to increase transferrin receptor mRNA levels is inhibited, and MSB increases the translation of a human growth hormone indicator mRNA bearing an IRE in its 5'-untranslated region. Nonetheless, MSB inhibits ferritin synthesis. Thus, menadione-induced oxidative stress leads to post-translational inactivation of both genetic and enzymatic functions of IRP-1 by a mechanism that lies beyond the "classical" Fe-S cluster switch and exerts multiple effects on cellular iron metabolism. (+info)Iron regulatory protein as an endogenous sensor of iron in rat intestinal mucosa. Possible implications for the regulation of iron absorption. (2/200)
Duodenal enterocytes adjust intestinal iron absorption to the body's state of iron repletion. Here we tested how iron supply from the blood modulates the RNA-binding activity of iron regulatory proteins (IRP-1 and IRP-2) in immature duodenal rat enterocytes, and whether the modulation is compatible with the hypothesis that IRPs, in turn, may regulate the expression of iron transport proteins in maturating enterocytes during migration to the villus tips. Tissue uptake of parenterally applied 59Fe along the duodenal crypt-villus axis was compared to local IRP-1 and IRP-2 activity and to duodenal 59Fe transport capacity 12 h, 48 h, and 72 h after intravenous iron administration to iron-deficient rats. IRP-1 and IRP-2 activity was significantly increased in iron-deficiency. 59Fe administrated from the blood side was almost exclusively taken up by crypt enterocytes. Accordingly, the activity of IRP-1 decreased at this site 12 h after parenteral iron administration, but remained high at the villus tips. After 48 h the bulk of 59Fe containing enterocytes had migrated to the villus tips. Correspondingly, IRP-1 activity was decreased at duodenal villus tips after 48 h. IRP-2 activity also tended to decrease, though the change was statistically not significant. IRP-2 activity remained significantly higher at duodenal villus tips than in crypts, even after 72 h. Intestinal iron absorption capacity decreased with the same delay as IRP-1 activity after intravenous iron administration. In the ileum 59Fe uptake from the blood and IRP activity showed no significant difference between crypt and villus region. Luminal administration of iron decreased duodenal IRP-1 and IRP-2 activity at tips and crypts within 2 h. Thus, recently absorbed iron becomes available to cytosolic IRP during its passage through the enterocyte. Our results are compatible with a role of IRPs in gearing the expression of intestinal iron transporters in the duodenal brushborder to the body's state of iron repletion. (+info)Ehrlichia chaffeensis and E. sennetsu, but not the human granulocytic ehrlichiosis agent, colocalize with transferrin receptor and up-regulate transferrin receptor mRNA by activating iron-responsive protein 1. (3/200)
Ehrlichia chaffeensis and E. sennetsu are genetically divergent obligatory intracellular bacteria of human monocytes and macrophages, and the human granulocytic ehrlichiosis (HGE) agent is an obligatory intracellular bacterium of granulocytes. Infection with both E. chaffeensis and E. sennetsu, but not HGE agent, in the acute monocytic leukemia cell line THP-1 almost completely inhibited by treatment with deferoxamine, a cell-permeable iron chelator. Transferrin receptors (TfRs) accumulated on both E. chaffeensis and E. sennetsu, but not HGE agent, inclusions in THP-1 cells or the cells of the promyelocytic leukemia cell line HL-60. Reverse transcription-PCR showed an increase in the level of TfR mRNA 6 h postinfection which peaked at 24 h postinfection with both E. chaffeensis and E. sennetsu infection in THP-1 or HL-60 cells. In contrast, HGE agent in THP-1 or HL-60 cells induced no increase in TfR mRNA levels. Heat treatment of E. chaffeensis or the addition of monodansylcadaverine, a transglutaminase inhibitor, 3 h prior to infection inhibited the up-regulation of TfR mRNA. The addition of oxytetracycline 6 h after E. chaffeensis infection caused a decrease in TfR mRNA which returned to the basal level by 24 h postinfection. These results indicate that both internalization and continuous proliferation of ehrlichial organisms or the production of ehrlichial proteins are required for the up-regulation of TfR mRNA. Results of electrophoretic mobility shift assays showed that both E. chaffeensis and E. sennetsu infection increased the binding activity of iron-responsive protein 1 (IRP-1) to the iron-responsive element at 6 h postinfection and remained elevated at 24 h postinfection. However, HGE agent infection had no effect on IRP-1 binding activity. This result suggests that activation of IRP-1 and subsequent stabilization of TfR mRNA comprise the mechanism of TfR mRNA up-regulation by E. chaffeensis and E. sennetsu infection. (+info)Ligand-induced structural alterations in human iron regulatory protein-1 revealed by protein footprinting. (4/200)
Human iron regulatory protein-1 (IRP-1) is a bifunctional protein that regulates iron metabolism by binding to mRNAs encoding proteins involved in iron uptake, storage, and utilization. Intracellular iron accumulation regulates IRP-1 function by promoting the assembly of an iron-sulfur cluster, conferring aconitase activity to IRP-1, and hindering RNA binding. Using protein footprinting, we have studied the structure of the two functional forms of IRP-1 and have mapped the surface of the iron-responsive element (IRE) binding site. Binding of the ferritin IRE or of the minimal regulatory region of transferrin receptor mRNA induced strong protections against proteolysis in the region spanning amino acids 80 to 187, which are located in the putative cleft thought to be involved in RNA binding. In addition, IRE-induced protections were also found in the C-terminal domain at Arg-721 and Arg-728. These data implicate a bipartite IRE binding site located in the putative cleft of IRP-1. The aconitase form of IRP-1 adopts a more compact structure because strong reductions of cleavage were detected in two defined areas encompassing residues 149 to 187 and 721 to 735. Thus both ligands of apo-IRP-1, the IRE and the 4Fe-4S cluster, induce distinct but overlapping alterations in protease accessibility. These data provide evidences for structural changes in IRP-1 upon cluster formation that affect the accessibility of residues constituting the RNA binding site. (+info)Ultraviolet A radiation induces immediate release of iron in human primary skin fibroblasts: the role of ferritin. (5/200)
In mammalian cells, the level of the iron-storage protein ferritin (Ft) is tightly controlled by the iron-regulatory protein-1 (IRP-1) at the posttranscriptional level. This regulation prevents iron acting as a catalyst in reactions between reactive oxygen species and biomolecules. The ultraviolet A (UVA) radiation component of sunlight (320-400 nm) has been shown to be a source of oxidative stress to skin via generation of reactive oxygen species. We report here that the exposure of human primary skin fibroblasts, FEK4, to UVA radiation causes an immediate release of "free" iron in the cells via proteolysis of Ft. Within minutes of exposure to a range of doses of UVA at natural exposure levels, the binding activity of IRP-1, as well as Ft levels, decreases in a dose-dependent manner. This decrease coincides with a significant leakage of the lysosomal components into the cytosol. Stabilization of Ft molecules occurs only when cells are pretreated with lysosomal protease inhibitors after UVA treatment. We propose that the oxidative damage to lysosomes that leads to Ft degradation and the consequent rapid release of potentially harmful "free" iron to the cytosol might be a major factor in UVA-induced damage to the skin. (+info)Human cytoplasmic aconitase (Iron regulatory protein 1) is converted into its [3Fe-4S] form by hydrogen peroxide in vitro but is not activated for iron-responsive element binding. (6/200)
Iron regulatory protein 1 (IRP1) regulates the synthesis of proteins involved in iron homeostasis by binding to iron-responsive elements (IREs) of messenger RNA. IRP1 is a cytoplasmic aconitase when it contains a [4Fe-4S] cluster and an RNA-binding protein after complete removal of the metal center by an unknown mechanism. Human IRP1, obtained as the pure recombinant [4Fe-4S] form, is an enzyme as efficient toward cis-aconitate as the homologous mitochondrial aconitase. The aconitase activity of IRP1 is rapidly lost by reaction with hydrogen peroxide as the [4Fe-4S] cluster is quantitatively converted into the [3Fe-4S] form with release of a single ferrous ion per molecule. The IRE binding capacity of IRP1 is not elicited with H(2)O(2). Ferrous sulfate (but not other more tightly coordinated ferrous ions, such as the complex with ethylenediamine tetraacetic acid) counteracts the inhibitory action of hydrogen peroxide on cytoplasmic aconitase, probably by replenishing iron at the active site. These results cast doubt on the ability of reactive oxygen species to directly increase IRP1 binding to IRE and support a signaling role for hydrogen peroxide in the posttranscriptional control of proteins involved in iron homeostasis in vivo. (+info)Iron-dependent regulation of transferrin receptor expression in Trypanosoma brucei. (7/200)
Transferrin is an essential growth factor for African trypanosomes. Here we show that expression of the trypanosomal transferrin receptor, which bears no structural similarity with mammalian transferrin receptors, is regulated by iron availability. Iron depletion of bloodstream forms of Trypanosoma brucei with the iron chelator deferoxamine resulted in a 3-fold up-regulation of the transferrin receptor and a 3-fold increase of the transferrin uptake rate. The abundance of expression site associated gene product 6 (ESAG6) mRNA, which encodes one of the two subunits of the trypanosome transferrin receptor, is regulated 5-fold by a post-transcriptional mechanism. In mammalian cells the stability of transferrin receptor mRNA is controlled by iron regulatory proteins (IRPs) binding to iron-responsive elements (IREs) in the 3'-untranslated region (UTR). Therefore, the role of a T. brucei cytoplasmic aconitase (TbACO) that is highly related to mammalian IRP-1 was investigated. Iron regulation of the transferrin receptor was found to be unaffected in Deltaaco::NEO/Deltaaco::HYG null mutants generated by targeted disruption of the TbACO gene. Thus, the mechanism of post-transcriptional transferrin receptor regulation in trypanosomes appears to be distinct from the IRE/IRP paradigm. The transferrin uptake rate was also increased when trypanosomes were transferred from medium supplemented with foetal bovine serum to medium supplemented with sera from other vertebrates. Due to varying binding affinities of the trypanosomal transferrin receptor for transferrins of different species, serum change can result in iron starvation. Thus, regulation of transferrin receptor expression may be a fast compensatory mechanism upon transmission of the parasite to a new host species. (+info)Regulation of iron metabolism in murine J774 macrophages: role of nitric oxide-dependent and -independent pathways following activation with gamma interferon and lipopolysaccharide. (8/200)
To elucidate the pathways by which nitric oxide (NO) influences macrophage iron metabolism, the uptake, release, and intracellular distribution of iron in the murine macrophage cell line J774 has been investigated, together with transferrin receptor (TfR) expression and iron-regulatory protein (IRP1 and IRP2) activity. Stimulation of macrophages with interferon-gamma (IFN-gamma) and/or lipopolysaccharide (LPS) decreased Fe uptake from transferrin (Tf), and there was a concomitant downregulation of TfR expression. These effects were mediated by NO-dependent and NO-independent mechanisms. Addition of the NO synthase (NOS) inhibitor N-monomethyl arginine (NMMA) partially restored Fe uptake but either had no effect on or downregulated TfR expression, which suggests that NO by itself is able to affect iron availability. Analysis of the intracellular distribution of incorporated iron revealed that in IFN-gamma/LPS-activated macrophages there was a decreased amount and proportion of ferritin-bound iron and a compensatory increase in insoluble iron, which probably consists mainly of iron bound to intracellular organelles. Finally, although NO released by IFN-gamma/LPS-activated macrophages increased the iron-responsive element (IRE)-binding activity of both IRP1 and IRP2, IFN-gamma treatment decreased IRP2 activity in an NO-independent manner. This study demonstrates that the effect of IFN-gamma and/or LPS on macrophage iron metabolism is complex, and is not entirely due to either NO-or to IRP-mediated mechanisms. The overall effect is to decrease iron uptake, but not its utilization. (+info)Iron Regulatory Protein 1 (IRP1) is a protein that plays a crucial role in the post-transcriptional regulation of iron homeostasis in cells. It is involved in the detection of cellular iron levels and responds by modulating the translation and stability of messenger RNAs (mRNAs) that encode proteins essential for iron metabolism.
IRP1 can bind to specific sequences called Iron Responsive Elements (IREs) present in the untranslated regions of mRNAs. When cellular iron levels are low, IRP1 binds to IREs and inhibits the translation of mRNAs encoding proteins responsible for iron uptake and storage, while stabilizing mRNAs that encode proteins involved in iron mobilization. Conversely, when iron levels are high, IRP1 dissociates from IREs, allowing for the normal translation of these mRNAs and maintaining iron homeostasis within the cell.
It is important to note that IRP1 has dual functions: it can act as an Iron Regulatory Protein (IRP) when iron levels are low, and as a cytosolic aconitase (an enzyme in the citric acid cycle) when iron levels are sufficient. This ability to switch between these two roles is facilitated by the presence of a [4Fe-4S] cluster, which is sensitive to cellular iron levels. When iron is abundant, the [4Fe-4S] cluster assembles, converting IRP1 into its cytosolic aconitase form; when iron is scarce, the cluster disassembles, enabling IRP1 to bind IREs and regulate iron metabolism-related gene expression.
Iron Regulatory Protein 2 (IRP2) is a regulatory protein involved in the post-transcriptional control of iron homeostasis. It binds to specific sequences called Iron Responsive Elements (IREs) found in the untranslated regions of mRNAs encoding proteins involved in iron metabolism, such as ferritin and transferrin receptor.
When cellular iron levels are low, IRP2 binds to the IREs and prevents the degradation of iron-related mRNAs, leading to increased synthesis of iron uptake proteins and decreased synthesis of iron storage proteins. Conversely, when iron levels are high, IRP2 is degraded, allowing for the normal turnover and translation of these mRNAs.
IRP2 plays a crucial role in maintaining appropriate intracellular iron concentrations and protecting cells from iron-induced oxidative stress. Dysregulation of IRP2 has been implicated in various diseases, including anemia, neurodegenerative disorders, and cancer.
Iron-regulatory proteins (IRPs) are specialized RNA-binding proteins that play a crucial role in the post-transcriptional regulation of iron homeostasis in mammalian cells. They are named as such because they regulate the expression of genes involved in iron metabolism, primarily by binding to specific cis-acting elements known as iron-responsive elements (IREs) located within the untranslated regions (UTRs) of target mRNAs.
There are two main IRPs: IRP1 and IRP2. Both proteins contain an N-terminal RNA-binding domain that recognizes and binds to IREs, as well as a C-terminal region involved in protein-protein interactions and other regulatory functions. Under conditions of iron deficiency or oxidative stress, IRPs become activated and bind to IREs, leading to changes in mRNA stability, translation, or both.
IRP1 can exist in two distinct conformational states: an active RNA-binding form (when iron levels are low) and an inactive aconitase form (when iron levels are sufficient). In contrast, IRP2 is primarily regulated by protein degradation, with its stability being modulated by the presence or absence of iron.
By binding to IREs within mRNAs encoding proteins involved in iron uptake, storage, and utilization, IRPs help maintain cellular iron homeostasis through a variety of mechanisms, including:
1. Promoting translation of transferrin receptor 1 (TfR1) mRNA to increase iron import when iron levels are low.
2. Inhibiting translation of ferritin heavy chain and light chain mRNAs to reduce iron storage when iron levels are low.
3. Stabilizing the mRNA encoding divalent metal transporter 1 (DMT1) to enhance iron uptake under conditions of iron deficiency.
4. Promoting degradation of transferrin receptor 2 (TfR2) and ferroportin mRNAs to limit iron import and export, respectively, when iron levels are high.
Overall, the regulation of iron metabolism by IRPs is crucial for maintaining proper cellular function and preventing the accumulation of toxic free radicals generated by iron-catalyzed reactions.
In the context of medicine, iron is an essential micromineral and key component of various proteins and enzymes. It plays a crucial role in oxygen transport, DNA synthesis, and energy production within the body. Iron exists in two main forms: heme and non-heme. Heme iron is derived from hemoglobin and myoglobin in animal products, while non-heme iron comes from plant sources and supplements.
The recommended daily allowance (RDA) for iron varies depending on age, sex, and life stage:
* For men aged 19-50 years, the RDA is 8 mg/day
* For women aged 19-50 years, the RDA is 18 mg/day
* During pregnancy, the RDA increases to 27 mg/day
* During lactation, the RDA for breastfeeding mothers is 9 mg/day
Iron deficiency can lead to anemia, characterized by fatigue, weakness, and shortness of breath. Excessive iron intake may result in iron overload, causing damage to organs such as the liver and heart. Balanced iron levels are essential for maintaining optimal health.
Aconitate hydratase is an enzyme that catalyzes the reversible conversion of citrate to isocitrate in the Krebs cycle (also known as the tricarboxylic acid cycle or TCA cycle), which is a central metabolic pathway in the cell. This enzyme is also called aconitase or aconitate dehydratase.
The reaction catalyzed by aconitate hydratase involves two steps: first, the removal of a water molecule from citrate to form cis-aconitate; and second, the addition of a water molecule to cis-aconitate to form isocitrate. The enzyme binds to the substrate in such a way that it stabilizes the transition state between citrate and cis-aconitate, making the reaction more favorable.
Aconitate hydratase plays an important role in energy metabolism, as it helps generate NADH and FADH2, which are used to produce ATP through oxidative phosphorylation. Additionally, aconitate hydratase has been implicated in various diseases, including neurodegenerative disorders, cancer, and bacterial infections.
Iron-sulfur proteins are a group of metalloproteins that contain iron and sulfur atoms in their active centers. These clusters of iron and sulfur atoms, also known as iron-sulfur clusters, can exist in various forms, including Fe-S, 2Fe-2S, 3Fe-4S, and 4Fe-4S structures. The iron atoms are coordinated to the protein through cysteine residues, while the sulfur atoms can be in the form of sulfide (S2-) or sulfane (-S-).
These proteins play crucial roles in many biological processes, such as electron transfer, redox reactions, and enzyme catalysis. They are found in various organisms, from bacteria to humans, and are involved in a wide range of cellular functions, including energy metabolism, photosynthesis, nitrogen fixation, and DNA repair.
Iron-sulfur proteins can be classified into several categories based on their structure and function, such as ferredoxins, Rieske proteins, high-potential iron-sulfur proteins (HiPIPs), and radical SAM enzymes. Dysregulation or mutations in iron-sulfur protein genes have been linked to various human diseases, including neurodegenerative disorders, cancer, and mitochondrial disorders.
Ferritin is a protein in iron-metabolizing cells that stores iron in a water-soluble form. It is found inside the cells (intracellular) and is released into the bloodstream when the cells break down or die. Measuring the level of ferritin in the blood can help determine the amount of iron stored in the body. High levels of ferritin may indicate hemochromatosis, inflammation, liver disease, or other conditions. Low levels of ferritin may indicate anemia, iron deficiency, or other conditions.
Transferrin receptors are membrane-bound proteins found on the surface of many cell types, including red and white blood cells, as well as various tissues such as the liver, brain, and placenta. These receptors play a crucial role in iron homeostasis by regulating the uptake of transferrin, an iron-binding protein, into the cells.
Transferrin binds to two ferric ions (Fe3+) in the bloodstream, forming a complex known as holo-transferrin. This complex then interacts with the transferrin receptors on the cell surface, leading to endocytosis of the transferrin-receptor complex into the cell. Once inside the cell, the acidic environment within the endosome causes the release of iron ions from the transferrin molecule, which can then be transported into the cytoplasm for use in various metabolic processes.
After releasing the iron, the apo-transferrin (iron-free transferrin) is recycled back to the cell surface and released back into the bloodstream, where it can bind to more ferric ions and repeat the cycle. This process helps maintain appropriate iron levels within the body and ensures that cells have access to the iron they need for essential functions such as DNA synthesis, energy production, and oxygen transport.
In summary, transferrin receptors are membrane-bound proteins responsible for recognizing and facilitating the uptake of transferrin-bound iron into cells, playing a critical role in maintaining iron homeostasis within the body.
Apoferritins are the protein shells or apoproteins of ferritin molecules that are devoid of iron. Ferritin is a protein in cells that stores iron and releases it in a form that can be used by the body. Apoferritin can bind with iron ions to form ferritin. It has a hollow, spherical structure and is often used as a model for studying protein folding and assembly.
Iron chelating agents are medications that bind to iron in the body, forming a stable complex that can then be excreted from the body. These agents are primarily used to treat iron overload, a condition that can occur due to frequent blood transfusions or certain genetic disorders such as hemochromatosis. By reducing the amount of iron in the body, these medications can help prevent or reduce damage to organs such as the heart and liver. Examples of iron chelating agents include deferoxamine, deferasirox, and deferiprone.
RNA-binding proteins (RBPs) are a class of proteins that selectively interact with RNA molecules to form ribonucleoprotein complexes. These proteins play crucial roles in the post-transcriptional regulation of gene expression, including pre-mRNA processing, mRNA stability, transport, localization, and translation. RBPs recognize specific RNA sequences or structures through their modular RNA-binding domains, which can be highly degenerate and allow for the recognition of a wide range of RNA targets. The interaction between RBPs and RNA is often dynamic and can be regulated by various post-translational modifications of the proteins or by environmental stimuli, allowing for fine-tuning of gene expression in response to changing cellular needs. Dysregulation of RBP function has been implicated in various human diseases, including neurological disorders and cancer.
Iron metabolism disorders are a group of medical conditions that affect the body's ability to absorb, transport, store, or utilize iron properly. Iron is an essential nutrient that plays a crucial role in various bodily functions, including oxygen transportation and energy production. However, imbalances in iron levels can lead to several health issues.
There are two main types of iron metabolism disorders:
1. Iron deficiency anemia (IDA): This condition occurs when the body lacks adequate iron to produce sufficient amounts of hemoglobin, a protein in red blood cells responsible for carrying oxygen throughout the body. Causes of IDA may include inadequate dietary iron intake, blood loss, or impaired iron absorption due to conditions like celiac disease or inflammatory bowel disease.
2. Hemochromatosis: This is a genetic disorder characterized by excessive absorption and accumulation of iron in various organs, including the liver, heart, and pancreas. Over time, this excess iron can lead to organ damage and diseases such as cirrhosis, heart failure, diabetes, and arthritis. Hemochromatosis is typically caused by mutations in the HFE gene, which regulates iron absorption in the intestines.
Other iron metabolism disorders include:
* Anemia of chronic disease (ACD): A type of anemia that occurs in individuals with chronic inflammation or infection, where iron is not efficiently used for hemoglobin production due to altered regulation.
* Sideroblastic anemias: These are rare disorders characterized by the abnormal formation of ringed sideroblasts (immature red blood cells containing iron-laden mitochondria) in the bone marrow, leading to anemia and other symptoms.
* Iron-refractory iron deficiency anemia (IRIDA): A rare inherited disorder caused by mutations in the TMPRSS6 gene, resulting in impaired regulation of hepcidin, a hormone that controls iron absorption and distribution in the body. This leads to both iron deficiency and iron overload.
Proper diagnosis and management of iron metabolism disorders are essential to prevent complications and maintain overall health. Treatment options may include dietary modifications, iron supplementation, phlebotomy (bloodletting), or chelation therapy, depending on the specific disorder and its severity.
Dietary iron is a vital nutrient that plays a crucial role in the production of hemoglobin, a protein in red blood cells responsible for carrying oxygen throughout the body. It is also essential for various other bodily functions, including energy production and immune function.
There are two forms of dietary iron: heme and non-heme. Heme iron is found in animal products such as meat, poultry, and fish, while non-heme iron is found in plant-based foods such as beans, lentils, tofu, spinach, and fortified cereals.
The recommended daily intake of dietary iron varies depending on age, sex, and other factors. For example, adult men typically require 8 milligrams (mg) per day, while adult women need 18 mg per day. Pregnant women may require up to 27 mg per day, while breastfeeding women need around 9-10 mg per day.
It is important to note that the absorption of non-heme iron from plant-based foods can be enhanced by consuming them with vitamin C-rich foods or drinks, such as citrus fruits, strawberries, and bell peppers. On the other hand, certain substances such as tannins (found in tea and coffee) and phytates (found in whole grains and legumes) can inhibit the absorption of non-heme iron.
Deferoxamine is a medication used to treat iron overload, which can occur due to various reasons such as frequent blood transfusions or excessive iron intake. It works by binding to excess iron in the body and promoting its excretion through urine. This helps to prevent damage to organs such as the heart and liver that can be caused by high levels of iron.
Deferoxamine is an injectable medication that is typically administered intravenously or subcutaneously, depending on the specific regimen prescribed by a healthcare professional. It may also be used in combination with other medications to manage iron overload more effectively.
It's important to note that deferoxamine should only be used under the guidance of a medical professional, as improper use or dosing can lead to serious side effects or complications.
Homeostasis is a fundamental concept in the field of medicine and physiology, referring to the body's ability to maintain a stable internal environment, despite changes in external conditions. It is the process by which biological systems regulate their internal environment to remain in a state of dynamic equilibrium. This is achieved through various feedback mechanisms that involve sensors, control centers, and effectors, working together to detect, interpret, and respond to disturbances in the system.
For example, the body maintains homeostasis through mechanisms such as temperature regulation (through sweating or shivering), fluid balance (through kidney function and thirst), and blood glucose levels (through insulin and glucagon secretion). When homeostasis is disrupted, it can lead to disease or dysfunction in the body.
In summary, homeostasis is the maintenance of a stable internal environment within biological systems, through various regulatory mechanisms that respond to changes in external conditions.
Messenger RNA (mRNA) is a type of RNA (ribonucleic acid) that carries genetic information copied from DNA in the form of a series of three-base code "words," each of which specifies a particular amino acid. This information is used by the cell's machinery to construct proteins, a process known as translation. After being transcribed from DNA, mRNA travels out of the nucleus to the ribosomes in the cytoplasm where protein synthesis occurs. Once the protein has been synthesized, the mRNA may be degraded and recycled. Post-transcriptional modifications can also occur to mRNA, such as alternative splicing and addition of a 5' cap and a poly(A) tail, which can affect its stability, localization, and translation efficiency.
Cation transport proteins are a type of membrane protein that facilitate the movement of cations (positively charged ions) across biological membranes. These proteins play a crucial role in maintaining ion balance and electrical excitability within cells, as well as in various physiological processes such as nutrient uptake, waste elimination, and signal transduction.
There are several types of cation transport proteins, including:
1. Ion channels: These are specialized protein structures that form a pore or channel through the membrane, allowing ions to pass through rapidly and selectively. They can be either voltage-gated or ligand-gated, meaning they open in response to changes in electrical potential or binding of specific molecules, respectively.
2. Ion pumps: These are active transport proteins that use energy from ATP hydrolysis to move ions against their electrochemical gradient, effectively pumping them from one side of the membrane to the other. Examples include the sodium-potassium pump (Na+/K+-ATPase) and calcium pumps (Ca2+ ATPase).
3. Ion exchangers: These are antiporter proteins that facilitate the exchange of one ion for another across the membrane, maintaining electroneutrality. For example, the sodium-proton exchanger (NHE) moves a proton into the cell in exchange for a sodium ion being moved out.
4. Symporters: These are cotransporter proteins that move two or more ions together in the same direction, often coupled with the transport of a solute molecule. An example is the sodium-glucose cotransporter (SGLT), which facilitates glucose uptake into cells by coupling its movement with that of sodium ions.
Collectively, cation transport proteins help maintain ion homeostasis and contribute to various cellular functions, including electrical signaling, enzyme regulation, and metabolic processes. Dysfunction in these proteins can lead to a range of diseases, such as neurological disorders, cardiovascular disease, and kidney dysfunction.
Transferrin is a glycoprotein that plays a crucial role in the transport and homeostasis of iron in the body. It's produced mainly in the liver and has the ability to bind two ferric (Fe3+) ions in its N-lobe and C-lobe, thus creating transferrin saturation.
This protein is essential for delivering iron to cells while preventing the harmful effects of free iron, which can catalyze the formation of reactive oxygen species through Fenton reactions. Transferrin interacts with specific transferrin receptors on the surface of cells, particularly in erythroid precursors and brain endothelial cells, to facilitate iron uptake via receptor-mediated endocytosis.
In addition to its role in iron transport, transferrin also has antimicrobial properties due to its ability to sequester free iron, making it less available for bacterial growth and survival. Transferrin levels can be used as a clinical marker of iron status, with decreased levels indicating iron deficiency anemia and increased levels potentially signaling inflammation or liver disease.
Untranslated regions (UTRs) are segments of messenger RNA (mRNA) that do not contain information for the synthesis of proteins. They are located at the 5' end (5' UTR) and 3' end (3' UTR) of the mRNA, outside of the coding sequence (CDS). The 5' UTR contains regulatory elements that control translation initiation, while the 3' UTR contains sequences involved in mRNA stability, localization, and translation efficiency. These regions do not code for proteins but play a crucial role in post-transcriptional regulation of gene expression.
"Response elements" is a term used in molecular biology, particularly in the study of gene regulation. Response elements are specific DNA sequences that can bind to transcription factors, which are proteins that regulate gene expression. When a transcription factor binds to a response element, it can either activate or repress the transcription of the nearby gene.
Response elements are often found in the promoter region of genes and are typically short, conserved sequences that can be recognized by specific transcription factors. The binding of a transcription factor to a response element can lead to changes in chromatin structure, recruitment of co-activators or co-repressors, and ultimately, the regulation of gene expression.
Response elements are important for many biological processes, including development, differentiation, and response to environmental stimuli such as hormones, growth factors, and stress. The specificity of transcription factor binding to response elements allows for precise control of gene expression in response to changing conditions within the cell or organism.
Iron overload is a condition characterized by an excessive accumulation of iron in the body's tissues and organs, particularly in the liver, heart, and pancreas. This occurs when the body absorbs more iron than it can use or eliminate, leading to iron levels that are higher than normal.
Iron overload can result from various factors, including hereditary hemochromatosis, a genetic disorder that affects how the body absorbs iron from food; frequent blood transfusions, which can cause iron buildup in people with certain chronic diseases such as sickle cell anemia or thalassemia; and excessive consumption of iron supplements or iron-rich foods.
Symptoms of iron overload may include fatigue, joint pain, abdominal discomfort, irregular heartbeat, and liver dysfunction. If left untreated, it can lead to serious complications such as cirrhosis, liver failure, diabetes, heart problems, and even certain types of cancer. Treatment typically involves regular phlebotomy (removal of blood) to reduce iron levels in the body, along with dietary modifications and monitoring by a healthcare professional.
Hemochromatosis is a medical condition characterized by excessive absorption and accumulation of iron in the body, resulting in damage to various organs. It's often referred to as "iron overload" disorder. There are two main types: primary (hereditary) and secondary (acquired). Primary hemochromatosis is caused by genetic mutations that lead to increased intestinal iron absorption, while secondary hemochromatosis can be the result of various conditions such as multiple blood transfusions, chronic liver disease, or certain types of anemia.
In both cases, the excess iron gets stored in body tissues, particularly in the liver, heart, and pancreas, which can cause organ damage and lead to complications like cirrhosis, liver failure, diabetes, heart problems, and skin discoloration. Early diagnosis and treatment through regular phlebotomy (blood removal) or chelation therapy can help manage the condition and prevent severe complications.
Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.
The duodenum is the first part of the small intestine, immediately following the stomach. It is a C-shaped structure that is about 10-12 inches long and is responsible for continuing the digestion process that begins in the stomach. The duodenum receives partially digested food from the stomach through the pyloric valve and mixes it with digestive enzymes and bile produced by the pancreas and liver, respectively. These enzymes help break down proteins, fats, and carbohydrates into smaller molecules, allowing for efficient absorption in the remaining sections of the small intestine.
Heme is not a medical term per se, but it is a term used in the field of medicine and biology. Heme is a prosthetic group found in hemoproteins, which are proteins that contain a heme iron complex. This complex plays a crucial role in various biological processes, including oxygen transport (in hemoglobin), electron transfer (in cytochromes), and chemical catalysis (in peroxidases and catalases).
The heme group consists of an organic component called a porphyrin ring, which binds to a central iron atom. The iron atom can bind or release electrons, making it essential for redox reactions in the body. Heme is also vital for the formation of hemoglobin and myoglobin, proteins responsible for oxygen transport and storage in the blood and muscles, respectively.
In summary, heme is a complex organic-inorganic structure that plays a critical role in several biological processes, particularly in electron transfer and oxygen transport.
Iron-binding proteins, also known as transferrins, are a type of protein responsible for the transport and storage of iron in the body. They play a crucial role in maintaining iron homeostasis by binding free iron ions and preventing them from participating in harmful chemical reactions that can produce reactive oxygen species (ROS) and cause cellular damage.
Transferrin is the primary iron-binding protein found in blood plasma, while lactoferrin is found in various exocrine secretions such as milk, tears, and saliva. Both transferrin and lactoferrin have a similar structure, consisting of two lobes that can bind one ferric ion (Fe3+) each. When iron is bound to these proteins, they are called holo-transferrin or holo-lactoferrin; when they are unbound, they are referred to as apo-transferrin or apo-lactoferrin.
Iron-binding proteins have a high affinity for iron and can regulate the amount of free iron available in the body. They help prevent iron overload, which can lead to oxidative stress and cellular damage, as well as iron deficiency, which can result in anemia and other health problems.
In summary, iron-binding proteins are essential for maintaining iron homeostasis by transporting and storing iron ions, preventing them from causing harm to the body's cells.
Hepcidin is a peptide hormone primarily produced in the liver that plays a crucial role in regulating iron homeostasis within the body. It acts by inhibiting the absorption of dietary iron in the intestines and the release of iron from storage sites, such as macrophages, into the bloodstream. By reducing the amount of iron available for use, hepcidin helps prevent excessive iron accumulation in tissues, which can be harmful and contribute to the development of various diseases, including iron overload disorders and certain types of anemia. The production of hepcidin is regulated by several factors, including iron levels, inflammation, and erythropoiesis (the production of red blood cells).
'Gene expression regulation' refers to the processes that control whether, when, and where a particular gene is expressed, meaning the production of a specific protein or functional RNA encoded by that gene. This complex mechanism can be influenced by various factors such as transcription factors, chromatin remodeling, DNA methylation, non-coding RNAs, and post-transcriptional modifications, among others. Proper regulation of gene expression is crucial for normal cellular function, development, and maintaining homeostasis in living organisms. Dysregulation of gene expression can lead to various diseases, including cancer and genetic disorders.
Cytosol refers to the liquid portion of the cytoplasm found within a eukaryotic cell, excluding the organelles and structures suspended in it. It is the site of various metabolic activities and contains a variety of ions, small molecules, and enzymes. The cytosol is where many biochemical reactions take place, including glycolysis, protein synthesis, and the regulation of cellular pH. It is also where some organelles, such as ribosomes and vesicles, are located. In contrast to the cytosol, the term "cytoplasm" refers to the entire contents of a cell, including both the cytosol and the organelles suspended within it.
A base sequence in the context of molecular biology refers to the specific order of nucleotides in a DNA or RNA molecule. In DNA, these nucleotides are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, uracil (U) takes the place of thymine. The base sequence contains genetic information that is transcribed into RNA and ultimately translated into proteins. It is the exact order of these bases that determines the genetic code and thus the function of the DNA or RNA molecule.
Protein biosynthesis is the process by which cells generate new proteins. It involves two major steps: transcription and translation. Transcription is the process of creating a complementary RNA copy of a sequence of DNA. This RNA copy, or messenger RNA (mRNA), carries the genetic information to the site of protein synthesis, the ribosome. During translation, the mRNA is read by transfer RNA (tRNA) molecules, which bring specific amino acids to the ribosome based on the sequence of nucleotides in the mRNA. The ribosome then links these amino acids together in the correct order to form a polypeptide chain, which may then fold into a functional protein. Protein biosynthesis is essential for the growth and maintenance of all living organisms.
A cell line is a culture of cells that are grown in a laboratory for use in research. These cells are usually taken from a single cell or group of cells, and they are able to divide and grow continuously in the lab. Cell lines can come from many different sources, including animals, plants, and humans. They are often used in scientific research to study cellular processes, disease mechanisms, and to test new drugs or treatments. Some common types of human cell lines include HeLa cells (which come from a cancer patient named Henrietta Lacks), HEK293 cells (which come from embryonic kidney cells), and HUVEC cells (which come from umbilical vein endothelial cells). It is important to note that cell lines are not the same as primary cells, which are cells that are taken directly from a living organism and have not been grown in the lab.
Protein binding, in the context of medical and biological sciences, refers to the interaction between a protein and another molecule (known as the ligand) that results in a stable complex. This process is often reversible and can be influenced by various factors such as pH, temperature, and concentration of the involved molecules.
In clinical chemistry, protein binding is particularly important when it comes to drugs, as many of them bind to proteins (especially albumin) in the bloodstream. The degree of protein binding can affect a drug's distribution, metabolism, and excretion, which in turn influence its therapeutic effectiveness and potential side effects.
Protein-bound drugs may be less available for interaction with their target tissues, as only the unbound or "free" fraction of the drug is active. Therefore, understanding protein binding can help optimize dosing regimens and minimize adverse reactions.
Nucleic acid conformation refers to the three-dimensional structure that nucleic acids (DNA and RNA) adopt as a result of the bonding patterns between the atoms within the molecule. The primary structure of nucleic acids is determined by the sequence of nucleotides, while the conformation is influenced by factors such as the sugar-phosphate backbone, base stacking, and hydrogen bonding.
Two common conformations of DNA are the B-form and the A-form. The B-form is a right-handed helix with a diameter of about 20 Ã… and a pitch of 34 Ã…, while the A-form has a smaller diameter (about 18 Ã…) and a shorter pitch (about 25 Ã…). RNA typically adopts an A-form conformation.
The conformation of nucleic acids can have significant implications for their function, as it can affect their ability to interact with other molecules such as proteins or drugs. Understanding the conformational properties of nucleic acids is therefore an important area of research in molecular biology and medicine.
RNA (Ribonucleic Acid) is a single-stranded, linear polymer of ribonucleotides. It is a nucleic acid present in the cells of all living organisms and some viruses. RNAs play crucial roles in various biological processes such as protein synthesis, gene regulation, and cellular signaling. There are several types of RNA including messenger RNA (mRNA), ribosomal RNA (rRNA), transfer RNA (tRNA), small nuclear RNA (snRNA), microRNA (miRNA), and long non-coding RNA (lncRNA). These RNAs differ in their structure, function, and location within the cell.
I must clarify that "Iron Isotopes" is not a medical term, but rather a scientific concept from the field of physics and chemistry. However, I can certainly provide a general explanation of isotopes and then focus on iron isotopes specifically.
An isotope is a variant of a chemical element that has the same number of protons (and thus the same atomic number) but a different number of neutrons within its nucleus. This results in variations of the atomic mass of isotopes of the same element. Some isotopes are stable, while others are unstable and will decay over time into other elements or isotopes, a process called radioactive decay.
Iron (Fe) has four naturally occurring stable isotopes: Fe-54, Fe-56, Fe-57, and Fe-58. These iron isotopes have different numbers of neutrons in their nuclei, resulting in slightly different atomic masses. The most abundant iron isotope is Fe-56, which contains 26 protons and 30 neutrons in its nucleus.
In the context of human health, iron is an essential nutrient that plays a crucial role in various biological processes, such as oxygen transport and energy production. However, the concept of iron isotopes does not have a direct medical relevance, but it can be useful in scientific research related to fields like geochemistry, environmental science, or nuclear physics.
In the context of medical and biological sciences, a "binding site" refers to a specific location on a protein, molecule, or cell where another molecule can attach or bind. This binding interaction can lead to various functional changes in the original protein or molecule. The other molecule that binds to the binding site is often referred to as a ligand, which can be a small molecule, ion, or even another protein.
The binding between a ligand and its target binding site can be specific and selective, meaning that only certain ligands can bind to particular binding sites with high affinity. This specificity plays a crucial role in various biological processes, such as signal transduction, enzyme catalysis, or drug action.
In the case of drug development, understanding the location and properties of binding sites on target proteins is essential for designing drugs that can selectively bind to these sites and modulate protein function. This knowledge can help create more effective and safer therapeutic options for various diseases.
The liver is a large, solid organ located in the upper right portion of the abdomen, beneath the diaphragm and above the stomach. It plays a vital role in several bodily functions, including:
1. Metabolism: The liver helps to metabolize carbohydrates, fats, and proteins from the food we eat into energy and nutrients that our bodies can use.
2. Detoxification: The liver detoxifies harmful substances in the body by breaking them down into less toxic forms or excreting them through bile.
3. Synthesis: The liver synthesizes important proteins, such as albumin and clotting factors, that are necessary for proper bodily function.
4. Storage: The liver stores glucose, vitamins, and minerals that can be released when the body needs them.
5. Bile production: The liver produces bile, a digestive juice that helps to break down fats in the small intestine.
6. Immune function: The liver plays a role in the immune system by filtering out bacteria and other harmful substances from the blood.
Overall, the liver is an essential organ that plays a critical role in maintaining overall health and well-being.
An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.
"Iron radioisotopes" refer to specific forms of the element iron that have unstable nuclei and emit radiation. These isotopes are often used in medical imaging and treatment procedures due to their ability to be detected by specialized equipment. Common iron radioisotopes include Iron-52, Iron-55, Iron-59, and Iron-60. They can be used as tracers to study the distribution, metabolism, or excretion of iron in the body, or for targeted radiation therapy in conditions such as cancer.
Hydrogen peroxide (H2O2) is a colorless, odorless, clear liquid with a slightly sweet taste, although drinking it is harmful and can cause poisoning. It is a weak oxidizing agent and is used as an antiseptic and a bleaching agent. In diluted form, it is used to disinfect wounds and kill bacteria and viruses on the skin; in higher concentrations, it can be used to bleach hair or remove stains from clothing. It is also used as a propellant in rocketry and in certain industrial processes. Chemically, hydrogen peroxide is composed of two hydrogen atoms and two oxygen atoms, and it is structurally similar to water (H2O), with an extra oxygen atom. This gives it its oxidizing properties, as the additional oxygen can be released and used to react with other substances.
Leucine-Responsive Regulatory Protein (LRP) is not a well-established medical term, but it is a term used in biochemistry and molecular biology. It generally refers to a protein that is involved in the regulation of gene expression in response to leucine, an essential amino acid.
Leucine is known to stimulate protein synthesis and inhibit protein degradation in cells. LRP plays a crucial role in this process by acting as a sensor for leucine levels in the cell. When leucine levels are high, LRP becomes activated and binds to specific DNA sequences called response elements, which are located in the promoter regions of genes that are involved in protein synthesis and degradation. This binding leads to the activation or repression of these genes, thereby regulating protein metabolism in the cell.
In summary, Leucine-Responsive Regulatory Protein is a protein that regulates gene expression in response to leucine levels, playing a critical role in the regulation of protein synthesis and degradation in cells.
Recombinant proteins are artificially created proteins produced through the use of recombinant DNA technology. This process involves combining DNA molecules from different sources to create a new set of genes that encode for a specific protein. The resulting recombinant protein can then be expressed, purified, and used for various applications in research, medicine, and industry.
Recombinant proteins are widely used in biomedical research to study protein function, structure, and interactions. They are also used in the development of diagnostic tests, vaccines, and therapeutic drugs. For example, recombinant insulin is a common treatment for diabetes, while recombinant human growth hormone is used to treat growth disorders.
The production of recombinant proteins typically involves the use of host cells, such as bacteria, yeast, or mammalian cells, which are engineered to express the desired protein. The host cells are transformed with a plasmid vector containing the gene of interest, along with regulatory elements that control its expression. Once the host cells are cultured and the protein is expressed, it can be purified using various chromatography techniques.
Overall, recombinant proteins have revolutionized many areas of biology and medicine, enabling researchers to study and manipulate proteins in ways that were previously impossible.
A mutation is a permanent change in the DNA sequence of an organism's genome. Mutations can occur spontaneously or be caused by environmental factors such as exposure to radiation, chemicals, or viruses. They may have various effects on the organism, ranging from benign to harmful, depending on where they occur and whether they alter the function of essential proteins. In some cases, mutations can increase an individual's susceptibility to certain diseases or disorders, while in others, they may confer a survival advantage. Mutations are the driving force behind evolution, as they introduce new genetic variability into populations, which can then be acted upon by natural selection.
Oxidation-Reduction (redox) reactions are a type of chemical reaction involving a transfer of electrons between two species. The substance that loses electrons in the reaction is oxidized, and the substance that gains electrons is reduced. Oxidation and reduction always occur together in a redox reaction, hence the term "oxidation-reduction."
In biological systems, redox reactions play a crucial role in many cellular processes, including energy production, metabolism, and signaling. The transfer of electrons in these reactions is often facilitated by specialized molecules called electron carriers, such as nicotinamide adenine dinucleotide (NAD+/NADH) and flavin adenine dinucleotide (FAD/FADH2).
The oxidation state of an element in a compound is a measure of the number of electrons that have been gained or lost relative to its neutral state. In redox reactions, the oxidation state of one or more elements changes as they gain or lose electrons. The substance that is oxidized has a higher oxidation state, while the substance that is reduced has a lower oxidation state.
Overall, oxidation-reduction reactions are fundamental to the functioning of living organisms and are involved in many important biological processes.
Iron compounds refer to chemical substances that contain iron (Fe) combined with other elements. Iron is an essential mineral for the human body, playing a crucial role in various bodily functions such as oxygen transport, DNA synthesis, and energy production.
There are several types of iron compounds, including:
1. Inorganic iron salts: These are commonly used in dietary supplements and fortified foods to treat or prevent iron deficiency anemia. Examples include ferrous sulfate, ferrous gluconate, and ferric iron.
2. Heme iron: This is the form of iron found in animal products such as meat, poultry, and fish. It is more easily absorbed by the body compared to non-heme iron from plant sources.
3. Non-heme iron: This is the form of iron found in plant-based foods such as grains, legumes, fruits, and vegetables. It is not as well-absorbed as heme iron but can be enhanced by consuming it with vitamin C or other organic acids.
It's important to note that excessive intake of iron compounds can lead to iron toxicity, which can cause serious health problems. Therefore, it's essential to follow recommended dosages and consult a healthcare professional before taking any iron supplements.
Oxidative stress is defined as an imbalance between the production of reactive oxygen species (free radicals) and the body's ability to detoxify them or repair the damage they cause. This imbalance can lead to cellular damage, oxidation of proteins, lipids, and DNA, disruption of cellular functions, and activation of inflammatory responses. Prolonged or excessive oxidative stress has been linked to various health conditions, including cancer, cardiovascular diseases, neurodegenerative disorders, and aging-related diseases.
Oxygen is a colorless, odorless, tasteless gas that constitutes about 21% of the earth's atmosphere. It is a crucial element for human and most living organisms as it is vital for respiration. Inhaled oxygen enters the lungs and binds to hemoglobin in red blood cells, which carries it to tissues throughout the body where it is used to convert nutrients into energy and carbon dioxide, a waste product that is exhaled.
Medically, supplemental oxygen therapy may be provided to patients with conditions such as chronic obstructive pulmonary disease (COPD), pneumonia, heart failure, or other medical conditions that impair the body's ability to extract sufficient oxygen from the air. Oxygen can be administered through various devices, including nasal cannulas, face masks, and ventilators.
Western blotting is a laboratory technique used in molecular biology to detect and quantify specific proteins in a mixture of many different proteins. This technique is commonly used to confirm the expression of a protein of interest, determine its size, and investigate its post-translational modifications. The name "Western" blotting distinguishes this technique from Southern blotting (for DNA) and Northern blotting (for RNA).
The Western blotting procedure involves several steps:
1. Protein extraction: The sample containing the proteins of interest is first extracted, often by breaking open cells or tissues and using a buffer to extract the proteins.
2. Separation of proteins by electrophoresis: The extracted proteins are then separated based on their size by loading them onto a polyacrylamide gel and running an electric current through the gel (a process called sodium dodecyl sulfate-polyacrylamide gel electrophoresis or SDS-PAGE). This separates the proteins according to their molecular weight, with smaller proteins migrating faster than larger ones.
3. Transfer of proteins to a membrane: After separation, the proteins are transferred from the gel onto a nitrocellulose or polyvinylidene fluoride (PVDF) membrane using an electric current in a process called blotting. This creates a replica of the protein pattern on the gel but now immobilized on the membrane for further analysis.
4. Blocking: The membrane is then blocked with a blocking agent, such as non-fat dry milk or bovine serum albumin (BSA), to prevent non-specific binding of antibodies in subsequent steps.
5. Primary antibody incubation: A primary antibody that specifically recognizes the protein of interest is added and allowed to bind to its target protein on the membrane. This step may be performed at room temperature or 4°C overnight, depending on the antibody's properties.
6. Washing: The membrane is washed with a buffer to remove unbound primary antibodies.
7. Secondary antibody incubation: A secondary antibody that recognizes the primary antibody (often coupled to an enzyme or fluorophore) is added and allowed to bind to the primary antibody. This step may involve using a horseradish peroxidase (HRP)-conjugated or alkaline phosphatase (AP)-conjugated secondary antibody, depending on the detection method used later.
8. Washing: The membrane is washed again to remove unbound secondary antibodies.
9. Detection: A detection reagent is added to visualize the protein of interest by detecting the signal generated from the enzyme-conjugated or fluorophore-conjugated secondary antibody. This can be done using chemiluminescent, colorimetric, or fluorescent methods.
10. Analysis: The resulting image is analyzed to determine the presence and quantity of the protein of interest in the sample.
Western blotting is a powerful technique for identifying and quantifying specific proteins within complex mixtures. It can be used to study protein expression, post-translational modifications, protein-protein interactions, and more. However, it requires careful optimization and validation to ensure accurate and reproducible results.
Ferric compounds are inorganic compounds that contain the iron(III) cation, Fe3+. Iron(III) is a transition metal and can form stable compounds with various anions. Ferric compounds are often colored due to the d-d transitions of the iron ion. Examples of ferric compounds include ferric chloride (FeCl3), ferric sulfate (Fe2(SO4)3), and ferric oxide (Fe2O3). Ferric compounds have a variety of uses, including as catalysts, in dye production, and in medical applications.
HeLa cells are a type of immortalized cell line used in scientific research. They are derived from a cancer that developed in the cervical tissue of Henrietta Lacks, an African-American woman, in 1951. After her death, cells taken from her tumor were found to be capable of continuous division and growth in a laboratory setting, making them an invaluable resource for medical research.
HeLa cells have been used in a wide range of scientific studies, including research on cancer, viruses, genetics, and drug development. They were the first human cell line to be successfully cloned and are able to grow rapidly in culture, doubling their population every 20-24 hours. This has made them an essential tool for many areas of biomedical research.
It is important to note that while HeLa cells have been instrumental in numerous scientific breakthroughs, the story of their origin raises ethical questions about informed consent and the use of human tissue in research.
"Cells, cultured" is a medical term that refers to cells that have been removed from an organism and grown in controlled laboratory conditions outside of the body. This process is called cell culture and it allows scientists to study cells in a more controlled and accessible environment than they would have inside the body. Cultured cells can be derived from a variety of sources, including tissues, organs, or fluids from humans, animals, or cell lines that have been previously established in the laboratory.
Cell culture involves several steps, including isolation of the cells from the tissue, purification and characterization of the cells, and maintenance of the cells in appropriate growth conditions. The cells are typically grown in specialized media that contain nutrients, growth factors, and other components necessary for their survival and proliferation. Cultured cells can be used for a variety of purposes, including basic research, drug development and testing, and production of biological products such as vaccines and gene therapies.
It is important to note that cultured cells may behave differently than they do in the body, and results obtained from cell culture studies may not always translate directly to human physiology or disease. Therefore, it is essential to validate findings from cell culture experiments using additional models and ultimately in clinical trials involving human subjects.